package collection;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

//list接口
public class ListDemo1 {
    public static void main(String[] args) {
     /*   List<String> list = new ArrayList<>();
        list.add("one");
        list.add("two");
        list.add("three");
        list.add("four");
        list.add("five");
        list.add("one");
        System.out.println("list: " + list);
        String e=list.get(3);
        System.out.println(e);

        list.set(2,"six");
        System.out.println("list: " + list);
        String old=list.set(4,"seven");
        System.out.println(old);
        System.out.println("list"+list);
      */

        Random rand = new Random();
        List<Integer> list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            list.add(rand.nextInt(100));
        }
        System.out.println(list);
        for (int i = 0; i < list.size(); i++) {//遍历list集合
            list.set(i, list.get(i)*12);
        }
        System.out.println(list);




    }
}
